Linac Coherent Light Source (LCLS)
Low Level RF System
Injector Turn-on January 2007
September 19, 2006
September 19, 2006
Ron Akre, Dayle Kotturi
LCLS LLRF Review
akre@slac.stanford.edu, dayle@slac.stanford.edu
Safety First and Second and Third…..to Infinity
Hazards in the LLRF system
RF 1kW at 120Hz at 5uS = 0.6 Watts average,
2 Watt average amps at 2856MHz,
60W average amps at 476MHz
Hazards – RF Burns
Mitigation – Avoid contact with center conductor of energized
connectors. All employees working with LLRF systems are
required to have the proper training.
110VAC Connector
Hazards - Shock
Mitigation - Don’t touch conductors when plugging into outlet.
All chassis are inspected by UL trained inspector.
September 19, 2006
Ron Akre, Dayle Kotturi
LCLS LLRF Review
akre@slac.stanford.edu, dayle@slac.stanford.edu
Scope of Work – Injector Turn-on
Linac Sector 0 RF Upgrade
All 3 RF Chassis completed and Installed (Master Oscillator, Master Amp, PEP
phase Shifter
Control Module ready for test – higher phase noise levels if not installed
Sector 20 RF distribution system
Phase and Amplitude Controllers (PACs) – 6 units
Phase and Amplitude Detectors (PAD) – 2 units
Phased Locked Oscillator – Use SPPS unit for Turn On
LO Generator – Complete - 50% tested – looks good so far
Multiplier – 476MHz to 2856MHz – Complete 50% Tested
4 distribution chassis – Complete 102MHz, 2056MHz, 2830.5MHz
Laser Phase Measurement – in Design, diagnostic, not required for turn on –
Laser group wants it next week.
Distribution Amplifiers – 10W, 2850MHz on order – 10W, 102MHz Amp in
search Minicircuits has 5W and 50W
LLRF Control and Monitor System
1 kW Solid State S-Band Amplifiers – 5 units – Design Complete, In Fab
PAD – 12 units – 6 required for turn on
PAC – 6 units
Bunch Length Monitor Interface – awaiting Specs
Beam Phase Cavity
Will use single channel of PAD Chassis
Pill box cavity with 2 probes and 4 tuners – 2805MHz 3 units Complete
September 19, 2006
Ron Akre, Dayle Kotturi
LCLS LLRF Review
akre@slac.stanford.edu, dayle@slac.stanford.edu
LCLS Layout
P. Emma
September 19, 2006
Ron Akre, Dayle Kotturi
LCLS LLRF Review
akre@slac.stanford.edu, dayle@slac.stanford.edu
LLRF Control system spans Sector 20 off axis injector to beyond Sector 30
September 19, 2006
Ron Akre, Dayle Kotturi
LCLS LLRF Review
akre@slac.stanford.edu, dayle@slac.stanford.edu
LCLS RF Jitter Tolerance Budget
Lowest Noise Floor
Requirement
0.5deg X-Band = 125fS
Structure Fill time = 100nS
Noise floor = -111dBc/Hz
@ 11GHz 10MHz BW
-134dBc/Hz @ 476MHz
0.50
X-band
XRMS tolerance budget for
<12% rms peak-current jitter or
<0.1% rms final e− energy
jitter. All tolerances are rms
levels and the voltage and
phase tolerances per klystron
for L2 and L3 are Nk larger,
assuming uncorrelated errors,
where Nk is the number of
klystrons per linac.
P. Emma
September 19, 2006
Ron Akre, Dayle Kotturi
LCLS LLRF Review
akre@slac.stanford.edu, dayle@slac.stanford.edu
Slow Drift Tolerance Limits
(Top 4 rows for De/e < 5%, bottom 4 limited by feedback dynamic range)
Gun-Laser Timing
Bunch Charge
Gun RF Phase
Gun Relative Voltage
L0,1,X,2,3 RF Phase (approx.)
L0,1,X,2,3 RF Voltage (approx.)
(Tolerances are peak values, not rms)
2.4* deg-S
3.2
%
2.3 deg-S
0.6
%
5
deg-S
5
%
P. Emma, J, Wu
* for synchronization, this tolerance might be set to 1 ps (without arrival-time measurement)
September 19, 2006
Ron Akre, Dayle Kotturi
LCLS LLRF Review
akre@slac.stanford.edu, dayle@slac.stanford.edu
Distribution system
September 19, 2006
Ron Akre, Dayle Kotturi
LCLS LLRF Review
akre@slac.stanford.edu, dayle@slac.stanford.edu
Concerns of Previous Reviews
Installation of temperature stabilized cables can effect phase stability.
Working with cable shop on plan for installation
Triggers required to be synchronous with 476MHz may jitter
The highest frequency that triggers need to be synchronous with is 102MHz.
Procedurally triggers will be placed in the stable region
SPPS PLL design generates an internal pulse width based on a one-shot and
uses an old track and hold chip
Redesign of this chassis will be done next year and these comments will be taken
into consideration
LO Generator design uses internal trim caps and resistors to calibrate unit,
synchronization needs to be addressed, should consider SSB modulator
We are using internal trim caps and resistors - have not had a problem in the past
with these types of devices
The synchronization will be monitored and can be reset if it gets out of sync
The unit is a SSB modulator
Concerns of Hardware and Software being disconnected from each other and
the review committee would also like to better understand the software.
The LLRF Hardware effort has been moved to the controls group and is now being
reviewed with the software.
September 19, 2006
Ron Akre, Dayle Kotturi
LCLS LLRF Review
akre@slac.stanford.edu, dayle@slac.stanford.edu
Linac Sector 0 RF Upgrade
LCLS must be compatible with the existing linac operation including PEP timing shifts
MAIN LINAC (SECTOR 0) RF/TIMING SYSTEM
Master Oscillator is
located 1.3 miles
from LCLS Injector
Measurements on
January 20, 2006
at Sector 21
show 30fS rms jitter
in a bandwidth from
10Hz to 10MHz
1
476MHz
PEP PHASE
MASTER
OSCILLATOR SHIFTER
+-720 Degrees
in 0.5mS
Sum
Fiducial
to RF
MASTER
AMPLIFIERS
476MHz
SLC COUNTDOW N
CHASSIS 476MHz
Divide to 8.5MHz
8.5MHz
360Hz Line
Sync.
360Hz
PEP PHASE SHIFT ON MAIN DRIVE LINE
Master Trigger
Generator MTG
Syncs Fiducial to
8.5MHz Damping Ring
and 360Hz Power Line
Main Drive Line (MDL)
476MHz RF plus
360Hz Fiducial
To:
Main Linac - 2 miles
Damping Rings
PEP
NLCTA
End Station A
FFTB
ORION
1.3 Miles to
LCLS Injector
Fiducial Generator
Syncronized to:
360Hz Power Line
8.5MHz Damping Ring
476MHz RF Distribution
MDL RF with TIMING Pulse – Sync to DR
September 19, 2006
Ron Akre, Dayle Kotturi
LCLS LLRF Review
akre@slac.stanford.edu, dayle@slac.stanford.edu
20
PEP II Phase Shifter
10kHz freq shift 1.2Vpp IQ in
Agilent E4407B
10
0
-10
dBm
-20
-30
-40
-50
-60
-70
-80
-90
-100
475950000
475970000
475990000
476010000
476030000
476050000
Frequency
September 19, 2006
Ron Akre, Dayle Kotturi
LCLS LLRF Review
akre@slac.stanford.edu, dayle@slac.stanford.edu
Linac Sector 0 RF Upgrade Status
New Low Noise Master Oscillator – Done
New Low Noise PEP Phase Shifter
RF Chassis – Done
Control Chassis – Ready for installation
New Low Noise Master Amplifier – Done
Main Drive Line Coupler in Sector 21 – Done
Measurements
Noise floor on 476MHz of -156dBc/Hz
Integrated jitter from 10Hz to 10MHz of 30fS
September 19, 2006
Ron Akre, Dayle Kotturi
LCLS LLRF Review
akre@slac.stanford.edu, dayle@slac.stanford.edu
RF System Topology / Specifications
Linac
Sector 0 RF
Number of cables per device
Reference cables are
8ft and can drift +-50fS
MDL
L0, L1 - 5 Klystrons
Specifications
100fS rms jitter
+-2.3pS drift
L2 - 4 Sectors
Specifications
70fS rms jitter
+-5pS drift
L3 - 6 Sectors
Specifications
150fS rms jitter
+-5pS drift
476MHz PLL
2830.5MHz LO
Amp / Splitter
PAD
Laser
1
RF Gun
5
2
L0A
Phase Cavity
2
L0B
2
L1S
4
L1X
2
L2 Ref
1
Laser
RF Gun
L0A
Phase Cavity
L0B
L1S
L1X
L2 Ref
Cable Drift Based on
Temperature variations
and temp co of 5ppm/degC
Most Devices
are in tunnel
+-680fS
Laser
+-370fS
RF Gun
+-310fS
L0A
+-240fS
Phase Cavity
+-240fS
L0B
+-140fS
+-160fS
+-500fS
RF HUT
September 19, 2006
Ron Akre, Dayle Kotturi
LCLS LLRF Review
akre@slac.stanford.edu, dayle@slac.stanford.edu
L1S
L1X
L2 Ref
Sector 20 RF Distribution
Main Drive Line (MDL)
476MHz RF
360Hz Fiducial
From Sector 0 (2km)
LCLS Sector 20 RF Reference System
MDL to Linac Sectors 21 to 30
PEP and Research Yard
RF HUT Coupler
476MHz Ref. 80uW
FSJ4-50 0.8dB/30ft
Existing
TIMING SYSTEM
FIDO Output
120Hz
TRBR
119MHz
380-208-38
476MHz Amp
30dB Gain 19dBm
Track/Hold
TRBR
RF MONITOR
PAD
LCLS 476MHz PLL
4x 476MHz
13dBm OUT
+13dBm in
+13dBm in
380-208-22
476MHz to 2856MHz
MULTIPLIER
380-208-22
476MHz to 2856MHz
MULTIPLIER
+17dBm out
RF CONTROL
SPAC
LO and 102MHz resync by
adjusting 2856MHz PAC while
monitoring S21 2856MHz
Laser resync with laser PAC
while monitoring difference in
119MHz laser and FIDO out
LASER Diode
Measurement
RF CONTROL
SPAC
119MHz
0dBm OUT
+17dBm out
LASER Diode
Output
RF CONTROL
SPAC
4 x +13dBm out
Sample and Hold PLL
with DAC offset adjust
and Error Monitor
119MHz Phase
LASER
Reference
476MHz
LASER LOCK
Reference
LCLS LLRF 476MHz Linac Ref.
Phase Noise and Timing
2830.5MHz LO Gen
IQ Modulator to adjust
2830.5MHz to 2856MHz Phase
LO Phase Monitor
Divide 112 to 25.5MHz
SSB Mix to 2830.5MHz
4X to 102MHz
LO Phase Monitor
RF MONITOR PAD
RF MONITOR PAD
25.5MHz out
102MHz out
RF CONTROL
SPAC
2830.5MHz out
RF CONTROL
SPAC
2856MHz
2Watt Amplifier
102MHz
2Watt Amplifier
2830.5MHz
2Watt Amplifier
Diode Detector
Diode Detector
Diode Detector
2856MHz
16 Way Distribution
20dBm each
Gun
L0A
L0B
L0TCAV
L1S
L1X
LINAC
EXPERIMENTS
2856MHz
2856MHz in
102MHz
Digitizer Clocks
16 Way Distribution
26dBm each
LO Phase Monitor
RF MONITOR
PAD
2830.5MHz LO
16 Way Distribution
20dBm each
Gun
L0A
L0B
L0TCAV
L1S
L1X
Gun
L0A
L0B
L0TCAV
L1S
L1X
LO Phase Monitor
RF MONITOR PAD
2856MHz from Sector 21
LO Phase Monitor
RF MONITOR PAD
September 19, 2006
Ron Akre, Dayle Kotturi
LCLS LLRF Review
akre@slac.stanford.edu, dayle@slac.stanford.edu
and
119MHz
2830.5MHz Generator
B. Hong
September 19, 2006
Ron Akre, Dayle Kotturi
LCLS LLRF Review
akre@slac.stanford.edu, dayle@slac.stanford.edu
Phase Noise Measurements
Noise Floors Lower Than
Expected Values which are
Lower than Requirements
By J. Frisch
September 19, 2006
Ron Akre, Dayle Kotturi
LCLS LLRF Review
akre@slac.stanford.edu, dayle@slac.stanford.edu
Sector 20 RF Distribution System Status
Phase Locked Oscillator – 476MHz – Done for now
Initial Turn On use SPPS Oscillator
Will modify control to achieve better stability during 2007
LO Generator – 2830.5MHz - Built – 50% tested
Multipliers - 476MHz to 2856MHz – Built – 50% tested
Phase and Amplitude Control (PAC) Unit
See next section
Phase and Amplitude Detector (PAD) Unit
See next section
Distribution Amplifiers
2850MHz due mid October
102MHz search under way
Laser Phase Measurement System
May design DC PAD control board
September 19, 2006
Ron Akre, Dayle Kotturi
LCLS LLRF Review
akre@slac.stanford.edu, dayle@slac.stanford.edu
LLRF Distribution Schedule
Racks to be installed in RF Hut – next week
RF Cables (On-site) to be pulled – mid October
RF Chassis – 50% complete
10 more chassis required for turn on, to be installed by
December
Remainder by March 2007
Testing of RF distribution system - December
Phase measurements of cables / looped
Ready for turn-on – Mid December
September 19, 2006
Ron Akre, Dayle Kotturi
LCLS LLRF Review
akre@slac.stanford.edu, dayle@slac.stanford.edu
Beam Phase Cavity Status
The cavity was moved to 2805MHz after concerns of the last review
about Dark Current were analyzed. Measurement of beam phase to
RF reference phase. The result will be used to correct timing of laser to
RF reference. 2805MHz cavity is located between L0A and L0B. Will
use RF PAD with 2830.5MHz LO for a 25.5MHz IF.
Electronics will use single
channel of PAD Chassis
Pill box cavity with 2
probes and 4 tuners
Cavity Electronics will use
single channel of RF
Monitor
Three cavities fabricated
September 19, 2006
Ron Akre, Dayle Kotturi
LCLS LLRF Review
akre@slac.stanford.edu, dayle@slac.stanford.edu
LLRF Control System
Distributed Control System
Microcontroller based IOC Control
(PAC) and Detector (PAD) Modules
Ethernet Switch
Central Feedback Computer
September 19, 2006
Ron Akre, Dayle Kotturi
LCLS LLRF Review
akre@slac.stanford.edu, dayle@slac.stanford.edu
Concerns of Previous Reviews
The Slow ADC can have problems with ground noise and should be
mounted on the RF board.
The Slow ADC is mounted on a separate board for the PAD and the same
board for the PAC. It is used to monitor various devices including external
thermocouples, RF power levels, and power supply voltages.
The system is being designed with too little diagnostics, at a minimum
the input power should be monitored for remote chassis.
The PAC is being designed with a monitor for input power. The LO on the
PAD, when used, will also be monitored.
The PAD and PAC systems should report missing, unexpected or
multiple trigger signals remotely.
The PAC currently has the ability to report missing triggers, but the features
have not yet been tested. The processor on the PAD has the capability to
do this also and this will be considered in the future if thought necessary.
September 19, 2006
Ron Akre, Dayle Kotturi
LCLS LLRF Review
akre@slac.stanford.edu, dayle@slac.stanford.edu
LLRF Control and Monitor System Klystron Station
TRIG
LCLS RF HUT
2830.5MHz LO
Amp / Splitter
TCAV
20-5
RF Gun
20-6
L0A
20-7
L0B
20-8
L1S
21-1
L1X
21-2
ENET
Trig & Ethernet
3dBm
From Klystron Drive Coupler
LO
PAC OUT
PAD
KLY BEAM Voltage
SPARE
102MHz
Clock In
Out
LCLS RF HUT
102MHz Clock
Amp / Splitter
TCAV
20-5
RF Gun
20-6
L0A
20-7
L0B
20-8
L1S
21-1
L1X
21-2
240ft = 2.5dB 1/2 Superflex
= 1.6dB LDF4
= 3dB LDF1
21dBm
13dBm
102MHz Clock In
LCLS RF HUT
2856MHz RF
Amp / Splitter
TCAV
20-5
RF Gun
20-6
L0A
20-7
L0B
20-8
L1S
21-1
L1X
21-2
240ft = 17dB 1/2 Superflex
= 10dB LDF4
PAC
3dBm
Coupled Out
In 2856MHz Out
SSSB Control
SSSB
Coupled Out
17dBm In 2856MHz Out
Control & Monitor
GATE
GATE
To IPA
Klystron Drive from
BCS
Trig & Ethernet
RF HUT
ENET
TRIG
140ft = 25dB 3/8 Superflex
KLYSTRON STATION
September 19, 2006
Ron Akre, Dayle Kotturi
LCLS LLRF Review
akre@slac.stanford.edu, dayle@slac.stanford.edu
RF & Temperature Signal Counts
for FeedBack exclude Klystron PADs
ADC Chan Cnt/FBK
Distribution/Laser
RF Gun
Beam Phase Cavity
L0-A Accelerator
L0-B Accelerator
L0-T Transverse Accelerator
L1-S Station 21-1 B, C, and D Acc
L1-X X-Band accelerator X-Band
S25-Tcav
S24-1, 2, & 3 Feedback
S29 and S30 Feedback
7/0
6/5
2/1
2/2
2/2
2/0
4/4
2/2
2/0
0
0
Hut PADs Temp. Mon.
1.5
1.5
0.5
0.5
0.5
0.5
1.0
0.5
0.5
September 19, 2006
Ron Akre, Dayle Kotturi
LCLS LLRF Review
akre@slac.stanford.edu, dayle@slac.stanford.edu
6
6
3
3
3
3
6
3
3
LLRF Control and Monitor System Status
1 kW Solid State S-Band Amplifiers – 5 units
1kW amplifier modules currently in test
Existing amplifier support design under review
Phase and Amplitude Detectors – 11 quad chan units
Control Board – Pre production delivered – may require 2nd
round.
RF Board – in layout
Phase and Amplitude Controllers – 6 units
Control board – Sent out for Pre production
RF Board – Pre-production in Fab.
September 19, 2006
Ron Akre, Dayle Kotturi
LCLS LLRF Review
akre@slac.stanford.edu, dayle@slac.stanford.edu
PAD
September 19, 2006
Ron Akre, Dayle Kotturi
LCLS LLRF Review
akre@slac.stanford.edu, dayle@slac.stanford.edu
CHAN 0
TEST PORT
RP SMA
CHAN 0
25.5MHz IF
FP BNC
4 X 16 bit ADC
102MHz Clock
LTC2208
Transformer Coupled Inputs
16bit DATA
Chan. 0
WCLK
IF
FILTER 25.5MHz BP
LO DIODE
DETECTOR
FP BNC
16bit DATA
RF LO
Chan. 1
MIXER
CPL7
WCLK
16bit DATA
Chan. 2
16bit DATA
MIXER
10dBm
Chan. 3
RF LO
IF
WCLK
FILTER 25.5MHz BP
16 bit
DATA
FIFO
64k words
CS/
CLK
FIFO
64k words
CONTROL /
Arcturus uC5282
Microcontroller Module
with 10/100 Ethernet
FIFO
64k words
RAW
ETHERNET
RF Board
WCLK
LO OUTPUT
2830.5MHz
RP N
CHAN 1
TEST PORT
FP N
FIFO
64k words
Control
CPLD
CHAN 1
RF INPUT
RP N
5VDC
0.8A x 2 Analog
CHAN 1
TEST PORT
RP SMA
CHAN 2
TEST PORT
RP SMA
CHAN 2
RF INPUT
RP N
CHAN 2
TEST PORT
FP N
CHAN 1
25.5MHz IF
FP BNC
IF
RF LO
MIXER
CPL7
RF Board
MIXER
RF LO
IF
LO OUTPUT
2830.5MHz
RP N
CHAN 3
TEST PORT
FP N
FILTER 25.5MHz BP
CHAN 3
RF INPUT
RP N
CHAN 3
TEST PORT
RP SMA
CLOCK IN CLOCK Mon
102MHz 102MHz
RP N
FP N
QSPI
5VDC
0.5A Digital
TRIG In
120Hz
RP BNC
CHAN 2
25.5MHz IF
FP BNC
FILTER 25.5MHz BP
LO DIODE
DETECTOR
FP BNC
LO INPUT
2830.5MHz
RP N
Control Board
ETHERNET COM
CHAN 0
RF INPUT
RP N
CHAN 0
TEST PORT
FP N
LO INPUT
2830.5MHz
RP N
PAD Block Diagram
CHAN 3
25.5MHz IF
FP BNC
20 pin ribbon
TRIG Mon
FP BNC
QSPI
RF Board Mixers Marki
Microwave M1-2040MEZ :
Amplifiers Sirenza SBW-5089 :
Slow ADC TI/BB ADS1218 :
Fast ADC LT LTC2208
24Bit
Analog
Input
Board
ANALOG IN ANALOG IN
Most PADs will consist of 2 RF Modules to
down convert 2856MHz to 25.5MHz, a 4
Channel, 16bit, digitizer control board, and
an 8 channel 24bit slow analog input.
September 19, 2006
Ron Akre, Dayle Kotturi
LCLS LLRF Review
akre@slac.stanford.edu, dayle@slac.stanford.edu
PAD RF Power Levels
# ADCs
Distribution
RF Gun Forward
RF Gun Probes
Beam Phase Cavity
L0-A Accelerator
L0-B Accelerator
L0-T Transverse Accelerator
L1-S Station 21-1 B, C, and D Acc
L1-X X-Band accelerator X-Band
S25-Tcav
S24-1, 2, & 3 Feedback
S29 and S30 Feedback
4
1
4
2
2
2
2
4
2
2
0
0
RF Power
PAD Power
10mW-100mW
10MW 10W-30W
10MW 10W-30W
100mW
30mW
60MW
120W
60MW
120W
0.5MW
0.5W-30W
15MW 30W-120W
20MW
2W
10MW
10W
September 19, 2006
Ron Akre, Dayle Kotturi
LCLS LLRF Review
akre@slac.stanford.edu, dayle@slac.stanford.edu
PAD 4 Chan ADC Board
25.5MHz 4 point IQ Data Analysis – SNR – 76dB Amplitude 76dB Phase
Noise Floor from below plots < -147dBc/Hz - SNR 65dB
25.5MHz Cross Talk from below plots < 100dB
Channel 0 data: Signal = -7.1dB Noise Level = -72.1dB
Channel 1 data: Signal = -112dB Noise Level = -79.3dB
Bin Width 1816Hz, 33dB
September 19, 2006
Ron Akre, Dayle Kotturi
LCLS LLRF Review
akre@slac.stanford.edu, dayle@slac.stanford.edu
PAD Software
Different LLRF apps need different calculations
There are 5 different algorithms:
AVG+STD – calculate average I and Q and variance of I
and Q
RF WF – calculate average I and Q
WF – calculate average of sample
RF WF2 – calculate average I and Q of two samples
IQ Cal – send 64K raw data waveform
Each channel on a PAD can run a different
algorithm
Each PAD can run in CALIBRATION or RUNNING
mode, which use different algorithms
September 19, 2006
Ron Akre, Dayle Kotturi
LCLS LLRF Review
akre@slac.stanford.edu, dayle@slac.stanford.edu
PAD Software
Data acquisition begins via timing trigger
Each PAD needs its own trigger so that it
can have its own delay
4 channels of 1024 16-bit integers at 102
MHz read in within 2 ms
September 19, 2006
Ron Akre, Dayle Kotturi
LCLS LLRF Review
akre@slac.stanford.edu, dayle@slac.stanford.edu
PAC
September 19, 2006
Ron Akre, Dayle Kotturi
LCLS LLRF Review
akre@slac.stanford.edu, dayle@slac.stanford.edu
PAC Block Diagram
2856MHz
Ref In
RP N
RF INPUT
Monitor
FP N
RF OUTPUT
Monitor
FP N
RF OUTPUT
To SSSB
RP N
I MONITOR Q MONITOR
FP BNC
FP BNC
H9
CLOCK
119MHz
RP N
H10
TRIGGER
EXT TRIG
Monitor TTL 120Hz
FP BNC
RP BNC
J2
H7
J3
RF Module
SSSB
SSSB
Gate Monitor Chassis
FP BNC
RP 15 Pin D
H6
SSSB
Trig
TTL
17 to 30uS
P5
MATCHING
FILTER
NETWORK
3
16bit DATA
Amp
I&Q MODULATOR
Amp
1
J5
LO
2 RF
4
Q
J4
MATCHING
FILTER
NETWORK
I
CLK
MAX5875
2 X 16 bit DAC
119MHz Clock
16bit DATA
(1MHz to 200MHz)
Q
CLK
XILINX
SPARTAN 3
FPGA
16 bit
DATA
CS/
CLK
AD8099 Diff Amp
Control
Control
CONTROL /
Arcturus uC5282
Microcontroller Module
with 10/100 Ethernet
ETHERNET RAW
ETHERNET
I
COM
Temperature
Monitor
RF INPUT
Monitor
Diode
FP BNC
NC
t
H12
SLOW ADCs
PAC Temp
IQ Temp
SSSB Temp
SSSB P-FWD
SSSB P-RFL
SSSB PWR
+5V
-12V
Temperature
t Monitor
Control Board
September 19, 2006
Ron Akre, Dayle Kotturi
LCLS LLRF Review
akre@slac.stanford.edu, dayle@slac.stanford.edu
PAC SSB Modulator Tests
58kHz lower side band test – Suppression of fundamental and opposite side
band is better than 60dB.
PAC SSB Modulator Tests
SN 3 May 5, 2006
0
-10
dBm
-20
-30
-40
-50
-60
-70
-80
-90
-100
-110
-120
475400000
475600000
475800000
476000000
476200000
476400000
476600000
Frequency
September 19, 2006
Ron Akre, Dayle Kotturi
LCLS LLRF Review
akre@slac.stanford.edu, dayle@slac.stanford.edu
PAC Software
PACs can run in either CALIBRATING or
RUNNING mode. A state machine keeps track.
If CALIBRATING, calibration waveforms are loaded
into FPGA and I and Q gains and offsets can be
adjusted.
If RUNNING, I and Q gains and offsets are fixed,
operational waveforms are loaded into FPGA and I
and Q adjustments can be applied at the
operational frequency.
September 19, 2006
Ron Akre, Dayle Kotturi
LCLS LLRF Review
akre@slac.stanford.edu, dayle@slac.stanford.edu
VME
September 19, 2006
Ron Akre, Dayle Kotturi
LCLS LLRF Review
akre@slac.stanford.edu, dayle@slac.stanford.edu
VME Software
Generic Feedback algorithm:
Phase and amplitude are calculated from I and Q
averages from each channel of the PAD
Phases are corrected by phase offset correction
Amplitudes are corrected by amplitude power correction
Phase and amplitudes are weighted by configurable
weighting factors to determine one average phase and
amplitude
Local or global feedback corrections are applied
Corrected phase and amplitude is converted to I and Q
Corrected I and Q values are sent to PAC
September 19, 2006
Ron Akre, Dayle Kotturi
LCLS LLRF Review
akre@slac.stanford.edu, dayle@slac.stanford.edu
VME Software
Beam Phasing Cavity algorithm (for Laser Timing):
Two sets of I and Q averages arrive (since there are two windows of
interest)
Phase1 is calculated from I1 and Q1
Phase2 is calculated from I2 and Q2
Measured beam phase is the y-intercept of the equation to the line
of phase as a function of FIFO position
Frequency is the slope of the line
Amplitude is calculated from I1 and Q1 (only)
Phase is corrected by phase offset correction
Amplitude is corrected by amplitude power correction
Local feedback corrections are applied
Corrected phase and amplitude is converted to I and Q
Corrected I and Q values are sent to laser PAC
September 19, 2006
Ron Akre, Dayle Kotturi
LCLS LLRF Review
akre@slac.stanford.edu, dayle@slac.stanford.edu
VME Software
Other calculations
For RF Reference Distribution
Phase and amplitude are calculated from I and Q
averages from each channel of the PAD
Phases are corrected by phase offset correction
Amplitudes are corrected by amplitude power
correction
Standard deviation of I and Q is calculated from I and
Q variances from each channel of the PAD
September 19, 2006
Ron Akre, Dayle Kotturi
LCLS LLRF Review
akre@slac.stanford.edu, dayle@slac.stanford.edu
Linac Station 21-1 Tests
September 19, 2006
Ron Akre, Dayle Kotturi
LCLS LLRF Review
akre@slac.stanford.edu, dayle@slac.stanford.edu
Linac 21-1 Test Set-up
MDL
Linac Ref Amp
New Equipment Added
For Tests
6x Multiplier
2830.5MHz
Generator
The 2856MHz out drives both the LO
generator and the PAC.
The klystron output coupler is used to
measure phase and amplitude with the
new PAD.
PAD
LO
CLK OUT
Klystron
Forward RF
SSSB
Existing
IPA
5045 KLYSTRON
SLED
Accelerator x3
September 19, 2006
Ron Akre, Dayle Kotturi
LCLS LLRF Review
akre@slac.stanford.edu, dayle@slac.stanford.edu
1
The SSSB drives the existing IPA chassis
CLK
2
The PAC output drives the SSSB.
2830.5MHz
PAC CLK
RF OUT
The 2830.5MHz LO and 102MHz CLK
Generator supplies the LO and CLK to
the PAD. A CLK output of the PAD drives
the PAC CLK.
102MHz
RF IN
Power Coupled out from 476MHz MDL
drives a 476MHz Amplifier which feeds a
6X Multiplier from 476MHz to 2856MHz.
Linac 21-1 Test Results
Tests were done in the gallery with no temperature regulation on cables.
Average RMS value of 2 second sliding average is 0.068 degrees.
Exponential Smoothing Yields
the Following Results.
Lowest noise is with a time
constant of about 2 points.
September 19, 2006
Ron Akre, Dayle Kotturi
LCLS LLRF Review
akre@slac.stanford.edu, dayle@slac.stanford.edu
END of TALK
September 19, 2006
Ron Akre, Dayle Kotturi
LCLS LLRF Review
akre@slac.stanford.edu, dayle@slac.stanford.edu
EPICS PANELS
Single Pulse
Diagnostic Panels for
PADs are Running
Remaining Software
History Buffer Select
PVs
Multi pulse data
analysis, correlation
plots
Local RF Feedback
loops
Links to global
Feedback loops
September 19, 2006
Ron Akre, Dayle Kotturi
LCLS LLRF Review
akre@slac.stanford.edu, dayle@slac.stanford.edu
End of LLRF RF Talk
Backup for RF Talk
Mostly Correct
September 19, 2006
Ron Akre, Dayle Kotturi
LCLS LLRF Review
akre@slac.stanford.edu, dayle@slac.stanford.edu
DESIGN PHILOSOPHY
Reliability is inversely proportional to the number of
connectors.
Stability is inversely proportional to the number of
connectors.
Measurement accuracy is inversely proportional to
the number of connectors and the amount of
Teflon, which is typically found in connectors.
Cost of maintenance is proportional to the number
of connectors.
September 19, 2006
Ron Akre, Dayle Kotturi
LCLS LLRF Review
akre@slac.stanford.edu, dayle@slac.stanford.edu
Electro-Optical Sampling
200 mm thick ZnTe crystal
Single-Shot
e-
Timing Jitter
(20 Shots)
<300 fs
Ti:Sapphire
laser
e- temporal information is encoded
on transverse profile of laser beam
170 fs rms
Adrian Cavalieri et al., U. Mich.
September 19, 2006
Ron Akre, Dayle Kotturi
LCLS LLRF Review
akre@slac.stanford.edu, dayle@slac.stanford.edu
MPS – PPS Issues
Addressed by Controls Group
Not Reviewed Here
Vacuum
New vacuum system summary to be fed to each
klystron existing MKSU.
PPS System
Injector modulators will be interlocked by Injector
PPS system.
PPS requirements for radiation from the injector
transverse accelerator needs to be determined.
Radiation levels will be measured during testing
in the Klystron Test Lab – Feb 06.
September 19, 2006
Ron Akre, Dayle Kotturi
LCLS LLRF Review
akre@slac.stanford.edu, dayle@slac.stanford.edu
Bandwidth of S-Band System
Upper Frequency Limit – 10MHz
Beam-RF interaction BW due to structure fill time
< 1.5MHz S-Band Accelerators and Gun
~10MHz X-Band and S-Band T Cav
Structure RF Bandwidth ~ 16MHz
5045 Klystron ~ 10MHz
Lower Frequency Limit – 10kHz
Fill time of SLED Cavity = 3.5uS about 100kHz
Laser – Needs to be measured ~ 10kHz
September 19, 2006
Ron Akre, Dayle Kotturi
LCLS LLRF Review
akre@slac.stanford.edu, dayle@slac.stanford.edu
Noise Levels
RF Reference Single Side Band (SSB) Noise Floor
2856MHz RF Distribution -144dBc/Hz
-174dBc/Hz @ 119MHz (24x = +28dB +2 for multiplier)
2830.5MHz Local Oscillator -138dBc/Hz
Integrated Noise
-138dBc/Hz at 10MHz = -65dBc = 32fS rms
SNR = 65dB for phase noise
Added noise from MIXER (LO noise same as RF)
SNR of 62dB
ADC noise levels
SNR of 70dB – 14bit ADS5500 at 102MSPS
September 19, 2006
Ron Akre, Dayle Kotturi
LCLS LLRF Review
akre@slac.stanford.edu, dayle@slac.stanford.edu
Phase Noise – Linac Sector 0
OLD MASTER OSCILLATOR
-133dBc/Hz at 476MHz
340fSrms jitter in 10MHz BW
NEW MASTER OSCILLATOR
-153dBc/Hz at 476 MHz
34fSrms jitter in 10MHz BW
Integrated Noise - Timing Jitter fs rms
Integral end
Integral start
Aug 17, 2004
Sector 30
Jan 20, 2006
Sector 21
5MHz
1M
1k
10kHz
100
100k
10k
10
27
30
33
38
75
82
15
19
20
20
8
17
September 19, 2006
Ron Akre, Dayle Kotturi
LCLS LLRF Review
akre@slac.stanford.edu, dayle@slac.stanford.edu
Sector 20 RF Distribution Cable Errors
Temperature Coefficient of 2.8ppm/ºF and
Cable length is 1200ºS/ft
All Cables except LASER are less than 100ft
Distances feet and errors in degrees S total range
RF Hut
Down
Linac
Wall
Injector Total
Unit
Ft degS ft degS
ft degS
ft degS ft degS DegS
Laser 8 0.054 25 0.017 10 0.014 10 0.007 85 0.58
0.68
Gun
8 0.054 25 0.017 10 0.014 10 0.007 40 0.27
0.37
L0-A
8 0.054 25 0.017 10 0.014 10 0.007 30 0.21
0.31
B Phas 8 0.054 25 0.017 10 0.014 10 0.007 20 0.14
0.24
L0-B
8 0.054 25 0.017 10 0.014 10 0.007 20 0.14
0.24
L0-T
8 0.054 25 0.017 10 0.014 10 0.007 10 0.07
0.17
L1-S
8 0.054 25 0.017 50 0.068
0.14
L1-X
8 0.054 25 0.017 60 0.081
0.16
Temperature Variations: RF Hut ±1ºF : Penetration ±0.1ºF : Linac : ±0.2ºF
Shield Wall ±0.1ºF : Injector ±1ºF
September 19, 2006
Ron Akre, Dayle Kotturi
LCLS LLRF Review
akre@slac.stanford.edu, dayle@slac.stanford.edu
RF System Topology / Specifications
Linac
Sector 0 RF
Number of cables per device
Reference cables are
8ft and can drift +-50fS
MDL
L0, L1 - 5 Klystrons
Specifications
100fS rms jitter
+-2.3pS drift
L2 - 4 Sectors
Specifications
70fS rms jitter
+-5pS drift
L3 - 6 Sectors
Specifications
150fS rms jitter
+-5pS drift
476MHz PLL
2830.5MHz LO
Amp / Splitter
PAD
Laser
1
RF Gun
5
2
L0A
Phase Cavity
2
L0B
2
L1S
4
L1X
2
L2 Ref
1
Laser
RF Gun
L0A
Phase Cavity
L0B
L1S
L1X
L2 Ref
Cable Drift Based on
Temperature variations
and temp co of 5ppm/degC
Most Devices
are in tunnel
+-680fS
Laser
+-370fS
RF Gun
+-310fS
L0A
+-240fS
Phase Cavity
+-240fS
L0B
+-140fS
+-160fS
+-500fS
RF HUT
September 19, 2006
Ron Akre, Dayle Kotturi
LCLS LLRF Review
akre@slac.stanford.edu, dayle@slac.stanford.edu
L1S
L1X
L2 Ref
RF Monitor Signal Counts
ADC Chan Cnt
Distribution (5~2850MHz, 4<500MHz)
RF Gun
Beam Phase Cavity
L0-A Accelerator
L0-B Accelerator
L0-T Transverse Accelerator
L1-S Station 21-1 B, C, and D Acc
L1-X X-Band accelerator X-Band
S25-Tcav
S24-1, 2, & 3 Feedback
S29 and S30 Feedback
Total Chassis
Total into Hut IOC
4
9
2
4
4
4
6
5
4
0
0
Chassis Count/Location
1Kly
1Kly
1Kly
1Kly
1Kly
1Kly
1Kly
7Kly
12
September 19, 2006
Ron Akre, Dayle Kotturi
LCLS LLRF Review
akre@slac.stanford.edu, dayle@slac.stanford.edu
1Hut
1.5Hut
0.5Hut
0.5Hut
0.5Hut
0.5Hut
1.0Hut
0.5Hut
6Hut
RF Control Signal Counts
Distribution (3~2850MHz, 3<500MHz)
RF Gun
Beam Phase Cavity
L0-A Accelerator
L0-B Accelerator
L0-T Transverse Accelerator
L1-S Station 21-1 B, C, and D accelerators
L1-X X-Band accelerator X-Band
S25-Tcav
S24-1, 2, & 3 Feedback
S29 and S30 Feedback
Total modulators
Totals at ~2856MHz
Total into Hut IOC
11 Fast
6 IQ Mod
1 Klystron
1 IQ mod
1 Klystron
1 Klystron
1 Klystron
1 Klystron
1 IQ Mod
1 Klystron
3 Klystrons
2 IQ modulators 476MHz
8 Slow
19 modulators
14 modulators
14 modulators
September 19, 2006
Ron Akre, Dayle Kotturi
LCLS LLRF Review
akre@slac.stanford.edu, dayle@slac.stanford.edu
LLRF Control and Monitor System
LLRF Control and Monitor System
1 kW Solid State S-Band Amplifiers – 5 units
Phase and Amplitude Monitors – 12 units
Phase and Amplitude Controllers – 6 units
Bunch Length Monitor Interface – Need Specifications
September 19, 2006
Ron Akre, Dayle Kotturi
LCLS LLRF Review
akre@slac.stanford.edu, dayle@slac.stanford.edu
RF Control
Required 13 Units
3
I Control
Includes Distribution
BXMP1007
I
1
RF In
17dBm
LO
RF 2
RF Out
17dBm
0dBm
Q
4
Q Control
2856MHz Input Monitor
2856MHz Output Monitor
2850MHz IQ Modulator
RF Control Module consist of the following:
Input Coupler, IQ Modulator, Amplifier, Output Coupler
Filters for I and Q inputs
September 19, 2006
Ron Akre, Dayle Kotturi
LCLS LLRF Review
akre@slac.stanford.edu, dayle@slac.stanford.edu
RF Monitor
Required 13 Chassis for Injector – Includes Distribution
LO 2830.5MHz : RF 2856MHz
IF 25.5MHz (8.5MHz x 3 in sync with timing fiducial)
Double-Balanced Mixer
Mixer IF to Amp and then Low Pass Filter
Filter output to ADC sampling at 102MSPS
RF LO
2830.5MHz Local Osc.
Amplifier
To ADC
IF
MIXER
2856MHz RF Signal
LTC2208 SNR = 77dBFS
25.5MHz BP FILTER
102MSPS
September 19, 2006
Ron Akre, Dayle Kotturi
LCLS LLRF Review
akre@slac.stanford.edu, dayle@slac.stanford.edu
1 kW Solid State S-Band Amplifiers
Design Complete
Two Units on the Shelf
Modules in house – and
tested
Support parts – Some
parts in house
Power Supplies, relays,
chassis on order
September 19, 2006
Ron Akre, Dayle Kotturi
LCLS LLRF Review
akre@slac.stanford.edu, dayle@slac.stanford.edu
SLAC Linac RF – New Control
MDL 476MHz
Next Sector
1mW
1W
6X
2856MHz
Existing
Phase
Reference
Line
3
SubBooster
Sub Drive Line
The new control system will tie in
to the IPA Chassis with 1kW of
drive power available. Reference
will be from the existing phase
reference line or the injector new
RF reference
To Next
Klystron
I
3kW
1
Phase &
Amplitude
Detector
Klystron
SLED
200MW
-45dB
Accelerator
1kW Amp
2856MHz
Q
4
IPA
High Power
Phase Shifter
Attenuator
20mW
Existing
System
LO
2 RF
IQ Modulator
I and Q will be controlled with a
16bit DAC running at 119MHz.
Waveforms to the DAC will be set
in an FPGA through a
microcontroller running EPICS on
RTEMS.
September 19, 2006
Ron Akre, Dayle Kotturi
LCLS LLRF Review
akre@slac.stanford.edu, dayle@slac.stanford.edu
Controls Talk
September 19, 2006
Ron Akre, Dayle Kotturi
LCLS LLRF Review
akre@slac.stanford.edu, dayle@slac.stanford.edu
LLRF Controls
Outline
Requirements
External Interfaces
Schedule
Date Needed
Prototype Completion Date
Hardware Order Date
Installation
Test Period
Design
Design Maturity (what reviews have been had)
State of Wiring Information
State of Prototype
September 19, 2006
Ron Akre, Dayle Kotturi
LCLS LLRF Review
akre@slac.stanford.edu, dayle@slac.stanford.edu
Requirements
At 120 Hz, meet phase/amp noise levels
defined as:
0.1% rms amplitude
100 fs rms in S-band (fill time = 850 ns)
125 fs rms in X-band (fill time = 100 ns)
All tolerances are rms levels and the voltage and
phase tolerances per klystron for L2 and L3 are
Nk larger, assuming uncorrelated errors, where
Nk is the number of klystrons per linac (L2 has
28; L3 has 48)
September 19, 2006
Ron Akre, Dayle Kotturi
LCLS LLRF Review
akre@slac.stanford.edu, dayle@slac.stanford.edu
Engineering Requirements
When beam is present, control will be done by
beam-based longitudinal feedback (except for Tcavs); when beam is absent, control will be done
by local phase and amplitude controller (PAC)
Adhere to LCLS Controls Group standards:
RTEMS, EPICS, Channel Access protocol
Ref: Why RTEMS? Study of open source real-time OS
Begin RF processing of high-powered structures
May 20, 2006
September 19, 2006
Ron Akre, Dayle Kotturi
LCLS LLRF Review
akre@slac.stanford.edu, dayle@slac.stanford.edu
External Interfaces
LLRF to LCLS global control system
PVs available for edm screens, archiving, etc over
controls network
LLRF VME to beam-based longitudinal feedback
from feedback: phase and amplitude corrections at 120
Hz over private ethernet
from LLRF: phase and amplitude values
(internal) LLRF VME to LLRF microcontrollers
from VME: triggers, corrected phase and amplitude
from microcontrollers: phase and amplitude averaged
values at 120 Hz, raw phase and amplitude values for
debug
September 19, 2006
Ron Akre, Dayle Kotturi
LCLS LLRF Review
akre@slac.stanford.edu, dayle@slac.stanford.edu
External Interfaces: Laser - Tcav
RF Phase and Amplitude correction at 120 Hz for:
laser, gun, L0-A, L0-B, L1-S, L1-X, T cav
In-house modules sharing VME crate for timing triggers
476 MHz RF Reference clock distributed to all 30 sectors in the Linac and beyond
Temperature monitors
RF Reference/4 = 119 MHz
stabilized to 50 fs jitter
T Cav
L1-X
L1-S
L0-B
L0-A
gun
Laser and RF ref
PAD
I and Q
Demodulator
F
I
F
O
s
A
D
C
Coldfire
CPU
running
RTEMS
and
EPICS
D
A
C
s
l
o
w
C
P
U
RF Reference*6 = 2856 MHz
stabilized to 50 fs jitter
VME Crate at S20
running
longitudinal,
beam-based
feedback
E
V
R
PAC
Coldfire
CPU
running
RTEMS
and
EPICS
FPGA
Private ethernet
4 kBytes at 120 Hz
D
A
C
D
A
C
1 trigger
for 4
channels
of 1k
samples
s
l
o
w
Private ethernet
8 kBytes at 120 Hz
Private ethernet
Controls gigabit ethernet (interface to MCC)
IQ Modulator
gives phase
and amplitude
control
1 trigger to travel
up to ½ sector
away
All except laser RF
La
) I
&Q F
t (I r R
Ou ato
RF ler
or
e
rat
cc
ele
A
cc
c/
/A
Q)
na
ac
Li z (I& Q)
Lin
H (I&
20 z
F 1 MH
r R 19
se 1
La r RF
se
100 mW
119 MHz
Laser
Oscillator
Solid State Sub Booster
1 kW
photodiode
Amps
Klystron
119 MHz
120 Hz
60 MW
photodiode
UV
n
SLED
cavity
Gun
&
(I
NB: For the gun, SLED
cavity is shorted out
Q
)
HPRF
240 MW
1 kW
1 kW
60 MW
10' accelerator
September 19, 2006
Ron Akre, Dayle Kotturi
LCLS LLRF Review
akre@slac.stanford.edu, dayle@slac.stanford.edu
External Interfaces: L2-L3
RF Phase and Amplitude correction at 120 Hz for:
laser, gun, L0-A, L0-B, L1-S, L1-X, T cav
In-house modules sharing VME crate for timing triggers
476 MHz RF Reference clock distributed to all 30 sectors in the Linac and beyond
Temperature monitors
RF Reference/4 = 119 MHz
stabilized to 50 fs jitter
T Cav
L1-X
L1-S
L0-B
L0-A
gun
Laser and RF ref
PAD
I and Q
Demodulator
F
I
F
O
s
A
D
C
Coldfire
CPU
running
RTEMS
and
EPICS
D
A
C
s
l
o
w
C
P
U
RF Reference*6 = 2856 MHz
stabilized to 50 fs jitter
VME Crate at S20
running
longitudinal,
beam-based
feedback
E
V
R
PAC
Coldfire
CPU
running
RTEMS
and
EPICS
FPGA
Private ethernet
4 kBytes at 120 Hz
D
A
C
D
A
C
1 trigger
for 4
channels
of 1k
samples
s
l
o
w
Private ethernet
8 kBytes at 120 Hz
Private ethernet
Controls gigabit ethernet (interface to MCC)
IQ Modulator
gives phase
and amplitude
control
1 trigger to travel
up to ½ sector
away
All except laser RF
La
) I
&Q F
t (I r R
Ou ato
RF ler
or
e
rat
cc
ele
A
cc
c/
/A
Q)
na
ac
Li z (I& Q)
Lin
H (I&
20 z
F 1 MH
r R 19
se 1
La r RF
se
100 mW
119 MHz
Laser
Oscillator
Solid State Sub Booster
1 kW
photodiode
Amps
Klystron
119 MHz
120 Hz
60 MW
photodiode
UV
n
SLED
cavity
Gun
&
(I
NB: For the gun, SLED
cavity is shorted out
Q
)
HPRF
240 MW
1 kW
1 kW
60 MW
10' accelerator
September 19, 2006
Ron Akre, Dayle Kotturi
LCLS LLRF Review
akre@slac.stanford.edu, dayle@slac.stanford.edu
Design
Design maturity (what reviews have been had):
RF/Timing Design, DOE Review, August 11, 2004
Akre_FAC_Oct04_RF_Timing, FAC Review, October, 2004
Low Level RF Controls Design, LCLS Week, January 25-27, 2005
Low Level RF, Lehman Review, May 10-12, 2005
LLRF Plans for Development and Testing of Controls, LCLS Week, July 21, 2005
Low Level RF Design, Presentation for Controls Group, Sept. 13, 2005
LLRF Preliminary Design review, SLAC, September 26, 2005
LCLS LLRF Control System - Kotturi, LLRF Workshop, CERN, October 10-13, 2005
LCLS LLRF System - Hong, LLRF Workshop, CERN, October 10-13, 2005
LLRF and Beam-based Longitudinal Feedback Readiness - Kotturi/Akre, LCLS Week, SLAC, October 24-26,
2005
LCLS Week LLRF and feedback - Kotturi/Allison, LCLS Week, SLAC, October 24-26, 2005
LLRF, LCLS System Concept Review/Preliminary Design Review, SLAC, November 16-17, 2005 Comments
LLRF Beam Phase Cavity Preliminary Design review, SLAC, November 30, 2005
Docs at: http://www.slac.stanford.edu/grp/lcls/controls/global/subsystems/llrf
State of wiring: percent complete Captar input will be given at time of presentation
State of prototype: PAD (1 chan ADC) and PAC boards built (shown on next pages).Testing.
September 19, 2006
Ron Akre, Dayle Kotturi
LCLS LLRF Review
akre@slac.stanford.edu, dayle@slac.stanford.edu
PAD – the monitor board
September 19, 2006
Ron Akre, Dayle Kotturi
LCLS LLRF Review
akre@slac.stanford.edu, dayle@slac.stanford.edu
PAD – the monitor board
RF Board
Line Drivers
Filters
2 X 16 bit ADC
119 or 102MHz Clock
LTC2208
Transformer Coupled Inputs
Control Board
FIFO 2 X 1k words
16bit DATA
25.5MHz IF
16 bit
DATA
Chan. 1
IF
WCLK
RF LO
16bit DATA
CS/
CLK
MIXER
Chan. 2
IF
WCLK
RF CHAN 2
INPUT
CONTROL /
Arcturus uC5282
Microcontroller Module
with 10/100 Ethernet
RF LO
MIXER
Control
LO INPUT
RF - 25.5MHz
EXTERNAL
CLOCK
102MHz
CPLD
EXTERNAL
TRIGGER
120Hz
September 19, 2006
Ron Akre, Dayle Kotturi
LCLS LLRF Review
akre@slac.stanford.edu, dayle@slac.stanford.edu
ETHERNET
RF CHAN 1
INPUT
PAC – the control board
September 19, 2006
Ron Akre, Dayle Kotturi
LCLS LLRF Review
akre@slac.stanford.edu, dayle@slac.stanford.edu
PAC – the control board
EXTERNAL
TRIGGER
TRIGGER
Monitor TTL 120Hz
60nS NIM
CLOCK
119MHz
SSSB
Chassis
MONITOR
PORTS
RF BOARD
MATCHING
FILTER
NETWORK
I&Q MODULATOR
3
16bit DATA
1
LO
2 RF
4
Q
XILINX
SPARTAN 3
FPGA
16 bit
DATA
CS/
CLK
CONTROL /
Arcturus uC5282
Microcontroller Module
with 10/100 Ethernet
AD8099 Diff Amp
2856MHz Ref
Control
Temperature
Monitor
DC Power
Supply
Monitors
t
Control
Temperature
Monitor
t
Thermocouples
DC Power
Supplies
ADCs
Control Board
September 19, 2006
Ron Akre, Dayle Kotturi
LCLS LLRF Review
akre@slac.stanford.edu, dayle@slac.stanford.edu
ETHERNET
I
CLK
MAX5875
2 X 16 bit DAC
119MHz Clock
16bit DATA
(1MHz to 200MHz)
Q
CLK
I
RF OUTPUT
To SSSB
Temperature Monitor
Forward Power 0-?V
Reflected Power 0-?V
Over Temp 0 or 12V
Power Supplie +12V
Power Supply -12V
SSSB
Trig
TTL
17 to 30uS
Additional Slides
The following two pages show an overview
of the LLRF control modules. From these
diagrams, counts of module types, as well as
function and location are seen.
September 19, 2006
Ron Akre, Dayle Kotturi
LCLS LLRF Review
akre@slac.stanford.edu, dayle@slac.stanford.edu
Overview of LLRF at Sector 20
RF phase and amplitude correction and global feedback at 120 Hz for LCLS LINAC S20
RF Dist’n
SPAC
SPAC
SPAC
SPAC
SPAC
PAD
PAC
Laser
Gun
L0-A
L0-B
PAC
PAD
PAD
Key:
Indicates located in RF Hut
Otherwise at Klystron
SPAC
PAD
PAC
PAD
PAD
PAD
PAD
Indicates may be needed
The maybe is included in
counts below
PAC
PAD
PAD
L0-Tcav
Eth
recvr
PAC
PAD
PAD
PAC
PAD
PAD
PAD
L1-S
C
P
U
VME Crate at S20
running
longitudinal,
beam-based
feedback.
E
V
R
L1-X
PAC
PAD
Beam Phase
Monitor
PAC
PAD
PAD
PAD
S20
Fast PACs:
Slow PACs (SPACs):
PADs:
VME crates:
8
6
19
1
September 19, 2006
Ron Akre, Dayle Kotturi
LCLS LLRF Review
akre@slac.stanford.edu, dayle@slac.stanford.edu
Overview of LLRF at Sector 24
RF phase and amplitude correction and global feedback at 120 Hz for LCLS LINAC S20
S24
L24-1
PAC
Fast PACs:
Slow PACs (SPACs):
PADs:
VME crates:
4
2
2
1
L24-2
PAC
L24-3
PAC
Tcav L24-8
PAC
PAD
PAD
Eth
recvr
C
P
U
E
V
R
VME Crate at S24
running
longitudinal,
beam-based
feedback.
S29
SPAC
S30
SPAC
September 19, 2006
Ron Akre, Dayle Kotturi
LCLS LLRF Review
akre@slac.stanford.edu, dayle@slac.stanford.edu
Beam Phase Monitor
R. Akre
A. Haase
B. Hong
D. Kotturi
V. Pacak
H. Schwarz
Preliminary Design Review
November 30, 2005
September 19, 2006
Ron Akre, Dayle Kotturi
LCLS LLRF Review
akre@slac.stanford.edu, dayle@slac.stanford.edu
Outline
•Purpose
•Specifications
•System outline
•Cavity
•Noise Levels
•Analysis
•Long Term Drifts
•Summary
September 19, 2006
Ron Akre, Dayle Kotturi
LCLS LLRF Review
akre@slac.stanford.edu, dayle@slac.stanford.edu
Laser Timing Stabilization Feedback
L INAC M DL R ef.
GU N R F F EEDB AC K
2856M Hz
R F R EF .
L CL S R F
Osci lla tor
In pu ts
GU N-C ELL 1-PH AS/AMPL
GU N-C ELL 2-PH AS/AMPL
L ASER
Actu ator s
GU N R F AC T UAT OR S
2856M H z R ef
PH ASE
ER RO R
GU N
PH AS
L 0A
Ac tu ator
L0, L 1 t o L2, L3
Phas e
PH ASE E RR OR
B etween
L 0, L 1 a nd L 2, L 3
GU N R F R EF.
GU N R F
AC TU AT ORS
L 0B
L ASER OSC IL LAT OR PH ASE
an d L ASER P OW ER
F EED B ACK
L 0-TC AV1
In pu ts
L ASER OSC . P H ASE
B UN CH C H ARGE
GU N-C ELL 1-AMPL /PH AS
GU N-C ELL 2-AMPL /PH AS
L ASER PH ASE & AM PLIT U DE
GU N R F AC T UAT OR S
B EAM PH ASE C AVIT Y
L 1-X
L ASER OSC IL LAT OR PH ASE
F EED B ACK
AM PL
L 1-S
In pu ts
B EAM PH ASE C AVIT Y
Actu ator s
L ASER PH ASE AC T UAT OR
K LYST R ON
AMPL IFI ER /
SLC C ON T ROL
GU N-F OR
Actu ator s
L ASER POW ER
L ASER PH ASE AC T UAT OR
T OROI D
RF GUN
PH AS
AM PL
L ASER OSC
OU T
L ASER R F R EF.
R ef erenc e
LASER
AMPLIFIER
W ATER T EMP
L ASER
POW ER
AC TU AT OR
GU N T U N E
F EED B ACK
L ASER PH ASE
AC TU AT OR
GU N-C ELL 1
L ASER OSC . P H ASE
L ASER PH ASE &
AMPL IT UD E?
In pu ts
GU N-F OR -PHAS
GU N-C ELL 1-PH AS
GU N-C ELL 2-PH AS
GU N-C ELL 2
Actu ator s
W ATER T EMP
B UN CH
C HAR GE
B EAM
PH ASE
C AVITY
Beam timing information from the beam phase monitor will be
used to apply corrections to the timing of the laser on the RF Gun.
September 19, 2006
Ron Akre, Dayle Kotturi
LCLS LLRF Review
akre@slac.stanford.edu, dayle@slac.stanford.edu
Specifications
Short term (2 second) timing jitter: 100fS rms
Long term (4 day) timing jitter: ±1pS
Range of the above accuracies is ±10pS
Data available at 120Hz
September 19, 2006
Ron Akre, Dayle Kotturi
LCLS LLRF Review
akre@slac.stanford.edu, dayle@slac.stanford.edu
System Outline
September 19, 2006
Ron Akre, Dayle Kotturi
LCLS LLRF Review
akre@slac.stanford.edu, dayle@slac.stanford.edu
Cavity
Frequency = 2856MHz
Q = 6000
Time Constant = 700nS
Temperature Coefficient = 50kH/°C
September 19, 2006
Ron Akre, Dayle Kotturi
LCLS LLRF Review
akre@slac.stanford.edu, dayle@slac.stanford.edu
System Critical Noise Levels and
Bandwidths
Cavity Signal – Bandwidth 500kHz
Local Oscillator – Noise Floor –143dBc/Hz
IF Filter – Bandwidth 4MHz
ADC – SNR at input 76dB
September 19, 2006
Ron Akre, Dayle Kotturi
LCLS LLRF Review
akre@slac.stanford.edu, dayle@slac.stanford.edu
System Critical Noise Levels and Bandwidths
Beam Phase Cavity
Monitor Port
30dBm pk
Coupler
Attenuator
23dBm pk
3dBm pk
-174dBm/Hz
-174dBm/Hz
In Tunnel
Monitor Port
MIXER
Generated from 119MHz Oscillator
Expected SSB Phase Noise Levels
Offset Hz dBc/Hz @ 2830.5MHz
10
-82
100
-96
1k
-124
10k
-144
20k
-146
1
2830.5MHz Oscillator
LO RF
30dBm pk
Filter - Butterworth
3rd order BandPass
2.5.5MHz Center
4.0MHz BW
2dB IL at 25.5MHz
Attenuator
IF
-3dBm pk
-146dBm/Hz
-143dBc/Hz
13dBm
-130dBm/Hz
-143dBc/Hz
ADC SNR 77dBFS
Amp
17dBm pk
2Vpp 10dBm pk
-129dBm/Hz
-143dBc/Hz
ADC LTC2208
2.25Vpp FS
Transformer coupled
102MHz Clock
Within filters BW
-135dBm/Hz
-143dBc/Hz
Beyond 5MHz from CF
<-155dBm/Hz
<-163dBc/Hz
Integrated Noise
-77dBc
September 19, 2006
Ron Akre, Dayle Kotturi
LCLS LLRF Review
akre@slac.stanford.edu, dayle@slac.stanford.edu
ADC Linear
Technologies LTC2208
16Bit 130MHz
September 19, 2006
Ron Akre, Dayle Kotturi
SNR 77.6dBFS 30MHz
in Clock 130MHz
SFDR 95dB
akre@slac.stanford.edu,
dayle@slac.stanford.edu
LCLS LLRF Review
Phase
Analysis
Time
Calculated
Beam Phase at
Beam Time
Measured
Data
Point 1
Measured
Data
Point 2
September 19, 2006
Ron Akre, Dayle Kotturi
LCLS LLRF Review
akre@slac.stanford.edu, dayle@slac.stanford.edu
I & Q from Waveform
Digital Down Mixing and Normalization
25.5MHz Digitized Signal
1
Digitized
Fraction ADC Full Scale
0.8
Input Signal
0.6
0.4
0.2
0
0.2
0.4
.
0.6
0
10
20
30
40
50
60
Point Number
September 19, 2006
Ron Akre, Dayle Kotturi
LCLS LLRF Review
akre@slac.stanford.edu, dayle@slac.stanford.edu
Optimization
Optimal Points to use for analysis is 16
point average at points 18 and 120
September 19, 2006
Ron Akre, Dayle Kotturi
LCLS LLRF Review
akre@slac.stanford.edu, dayle@slac.stanford.edu
Analysis Results
Standard deviation of result = 1.1e-4 or 6.3fS rms jitter
Signal level 20dB lower will give 63fS rms jitter
Sensitivity to frequency change = 0.6fS/2.8kH freq change
Sensitivity to timing change over +-10deg = 1:1
September 19, 2006
Ron Akre, Dayle Kotturi
LCLS LLRF Review
akre@slac.stanford.edu, dayle@slac.stanford.edu
Long Term Drifts
80ft (1M deg) of ½ inch superflex has TC of 4ppm/degC
Water temp tolerance is +-0.1degF = +-400fS drift
September 19, 2006
Ron Akre, Dayle Kotturi
LCLS LLRF Review
akre@slac.stanford.edu, dayle@slac.stanford.edu
Summary
Short term (2 second) timing jitter: 100fS rms
63fS rms
Long term (4 day) timing jitter: ±1pS
±0.8pS
Range of the above accuracies is ±10pS
Results
Data available at 120Hz
Simple algorithm in integer arithmetic will allow this
September 19, 2006
Ron Akre, Dayle Kotturi
LCLS LLRF Review
akre@slac.stanford.edu, dayle@slac.stanford.edu
Feedback Page 1
LOCAL FEEDBACK
LOCAL FEEDBACK
September 19, 2006
Ron Akre, Dayle Kotturi
LCLS LLRF Review
akre@slac.stanford.edu, dayle@slac.stanford.edu
Feedback Page 2
GLOBAL FEEDBACK
LOCAL FEEDBACK
September 19, 2006
Ron Akre, Dayle Kotturi
LCLS LLRF Review
akre@slac.stanford.edu, dayle@slac.stanford.edu
Feedback Page 3
GLOBAL FEEDBACK
LOCAL FEEDBACK
LOCAL FEEDBACK
September 19, 2006
Ron Akre, Dayle Kotturi
LCLS LLRF Review
akre@slac.stanford.edu, dayle@slac.stanford.edu
Feedback Page 4
GLOBAL FEEDBACK
September 19, 2006
Ron Akre, Dayle Kotturi
LCLS LLRF Review
akre@slac.stanford.edu, dayle@slac.stanford.edu
Feedback Page 5
GLOBAL FEEDBACK
September 19, 2006
Ron Akre, Dayle Kotturi
LCLS LLRF Review
akre@slac.stanford.edu, dayle@slac.stanford.edu
Feedback Page 6
September 19, 2006
Ron Akre, Dayle Kotturi
LCLS LLRF Review
akre@slac.stanford.edu, dayle@slac.stanford.edu